Objective—To evaluate fecal shedding of Giardia duodenalis,
Cryptosporidium parvum, Salmonella organisms,
and Escherichia coli O157:H7 from llamas in
California with respect to host factors and management
Animals—354 llamas from 33 facilities.
Procedure—Fecal specimens were collected and
examined for G duodenalis and C parvum by means
of immunofluorescent microscopy. Salmonella organisms
were cultured by placing feces into selenite
enrichment broth followed by selective media.
Escherichia coli O157:H7 was cultured by use of modified
tryptocase soy broth followed by sorbitol
MacConkey agar, with suspect colonies confirmed by
means of immunofluorescent microscopy.
Results—12 of 354 fecal specimens (3.4%) had G
duodenalis cysts. Younger llamas (crias) were more
likely to be shedding cysts, compared with older llamas.
Farm-level factors that increased the risk of
shedding were large numbers of yearlings on the
property (> 10), smaller pen sizes, large numbers of
crias born during the previous year (> 10), and large
pen or pasture populations (> 20). None of the 354
fecal specimens had C parvum oocysts. Seventy-six
(from 7 facilities) and 192 (from 22 facilities) llamas
were tested for Salmonella organisms and E coli
O157:H7, respectively. All fecal specimens had negative
results for these bacteria.
Conclusion and Clinical Relevance—Shedding of
G duodenalis was primarily limited to crias 1 to 4
months old. Llamas from properties with large numbers
of crias born in the previous year, resulting in
large numbers of yearlings in the current year, were at
greater risk of infection. In addition, housing llamas in
smaller pens or pastures and managing llamas and
crias in large groups also increased the risk of G duodenalis shedding.
(Am J Vet Res 2001;62:637–642)